|
|
Tong, C. E., Blundell, R., Papa, D. C., Smith, M., Kawamura, J., Gol'tsman, G., et al. (1999). An all solid-state superconducting heterodyne receiver at terahertz frequencies. IEEE Microw. Guid. Wave Lett., 9(9), 366–368.
Abstract: A superconducting hot-electron bolometer mixer-receiver operating from 1 to 1.26 THz has been developed. This heterodyne receiver employs two solid-state local oscillators each consisting of a Gunn oscillator followed by two stages of varactor frequency multiplication. The measured receiver noise temperature is 1350 K at 1.035 THz and 2700 K at 1.26 THz. This receiver demonstrates that tunable solid-state local oscillators, supplying only a few micro-watts of output power, can be used in terahertz receiver applications.
|
|
|
|
0kunev, 0., Dzardanov, A., Ekstrom, H., Jacobsson, S., Kollberg, E., Gol'tsman, G., et al. (1994). NbN hot electron waveguide mixer for 100 GHz operation. In Proc. 5th Int. Symp. Space Terahertz Technol. (pp. 214–224).
Abstract: NbN is a promising superconducting material used to develope hot- electron superconducting mixers with an IF bandwidth over 1 GHz. In the 100 GHz frequency range, the following parameters were obtained for NbN films 50 A thick: the noise temperature of the receiver (DSB) 1000 K; the conversion losses 10 d13, the IF bandwidth 1 GHz; the local oscillator power 1 /LW. An increase of NbN film thickness up to 80-100 A and increase of working temperature up to 7-8 K, and a better mixer matching may allow to broader the IF band up to 3 Gllz, to reduce the conversion losses down to 3-5 dB and the noise tempera- ture down to 200-300 K.
|
|
|
|
Mel’nikov, A. P., Gurvich, Y. A., Shestakov, L. N., & Gershenzon, E. M. (2001). Magnetic field effects on the nonohmic impurity conduction of uncompensated crystalline silicon. Jetp Lett., 73(1), 44–47.
Abstract: The impurity conduction of a series of crystalline silicon samples with the concentration of major impurity N ≈ 3 × 1016 cm−3 and with a varied, but very small, compensation K was measured as a function of the electric field E in various magnetic fields H-σ(H, E). It was found that, at K < 10−3 and in moderate E, where these samples are characterized by a negative nonohmicity (dσ(0, E)/dE < 0), the ratio σ(H, E)/σ(0, E) > 1 (negative magnetoresistance). With increasing E, these inequalities are simultaneously reversed (positive nonohmicity and positive magnetoresistance). It is suggested that both negative and positive nonohmicities are due to electron transitions in electric fields from impurity ground states to states in the Mott-Hubbard gap.
|
|
|
|
Gershenzon, E. M., Gol'tsman, G. N., Semenov, A. D., & Sergeev, A. V. (1992). Heating of electrons in resistive state of superconducting films. Detectors, mixers and switches. In Progress in High Temperature Superconductivity (Vol. 32, pp. 190–195).
|
|
|
|
Boyarskii, D. A., Gershenzon, V. E., Gershenzon, E. M., Gol'tsman, G. N., Ptitsina, N. G., Tikhonov, V. V., et al. (1996). On the possibility of determining the microstructural parameters of an oil-bearing layer from radiophysical measurement data. J. of Communications Technology and Electronics, 41(5), 408–414.
Abstract: A method for the reconstruction of microstructural properties of an oil-bearing rock from the spectral dependence of the transmission factor of submillimeter waves is proposed.
|
|
|
|
Blagosklonskaya, L. E., Gershenzon, E. M., Goltsman, G. N., & Elantev, A. I. (1978). Effect of strong magnetic-field on spectrum of hydrogen-like admixtures in semiconductors. In Izv. Akad. Nauk SSSR, Seriya Fizicheskaya (Vol. 42, pp. 1231–1234). Mezhdunarodnaya Kniga 39 Dimitrova Ul., 113095 Moscow, Russia.
|
|
|
|
Gershenzon, E. M., Gol'tsman, G. N., & Ptitsina, N. G. (1973). Submillimeter spectroscopy of semiconductors. Sov. Phys. JETP, 37(2), 299–304.
Abstract: The possibility is considered of carrying out submillimeter-wave spectral investigations of semiconductors by means of a high resolution spectrometer with backward-wave tubes. Results of a study of the excitation spectra of small impurities, D-(A +) centers and free excitons in germanium are presented.
|
|
|
|
Verevkin, A. A., Ptitsina, N. G., Smirnov, K. V., Gol'tsman, G. N., Voronov, B. M., Gershenzon, E. M., et al. (1997). Hot electron bolometer detectors and mixers based on a superconducting-two-dimensional electron gas-superconductor structure. In Proc. 4-th Int. Semicond. Device Research Symp. (pp. 163–166).
|
|
|
|
Gershenzon, E. M., Gol'tsman, G. N., & Kagane, M. L. (1977). Energy spectrum of acceptors in germanium and its response to a magnetic field. Sov. Phys. JETP, 45(4), 769–776.
Abstract: We investigated the spectrum of the submillimeter photoconductivity of p-Ge at helium temperatures and the effects of a magnetic field up to 40 kOe on the spectrum. A large number of lines of transitions between the excited states of the acceptors was observed, some of the lines were identified, and the energies of a number of spectral levels B, Al, Ga, In, and TI in Ge were identified. The results are compared with calculations and with experimental data obtained from the spectra of the photoexcitation of the ground state of the impurities. Using one transition as an example, we discuss the splitting of the excited states of acceptors in the magnetic field and under uniaxial compression.
|
|
|
|
Gershenzon, E. M., Gol'tsman, G. N., & Kagane, M. L. (1978). Observation of free carrier resonances in p-type germanium at submillimeter wavelengths. Sov. Phys. Solid State, 20(4), 573–579.
Abstract: The spectrum of hole resonances in pure p-Ge for submillimetre in quantizing magnetic fields has been studied and identified. Measurements of photoconductivity spectra of p-Ge were made in the wave range lambda = 2-0.3 mm at temp. of 4.2-15 deg K in magnetic fields H up to 40 Measurements at various frequencies showed that the position of a series of characteristic resonances depends on the frequency of the illumination. This is in line with theoretical conclusions about the effective mass of the carriers increasing with rise in the magnetic field as a result of the interaction of the edge of the valency band with the split spin-orbital interaction of the sub 7 exp + band and the conduction band. The relative intensity of the quantum resonance lines of the free holes depends on the excitation conditions.
|
|
|
|
Zorin, M., Milostnaya, I., Gol'tsman, G. N., & Gershenzon, E. M. (1997). Fast NbN superconducting switch controlled by optical radiation. IEEE Trans. Appl. Supercond., 7(2), 3734–3737.
Abstract: The switching time and the optical control power of the NbN superconducting switch have been measured. The device is based on the ultrathin film 5-8 nm thick patterned as a structure of several narrow parallel strips (/spl sim/1 /spl mu/m wide) connected to wide current leads. The current-voltage characteristic of the switch at temperature 4.2 K demonstrated a hysteresis due to DC current self-heating. We studied the superconducting-to-resistive state transition induced by both optical and bias-current excitations. The optical pulse duration was /spl sim/20 ps and the rise time of the current step was determined to be less than 50 ps. The optical pulse was delivered to the switch by the semiconductor laser through an optical fiber. We found that the measured switching time is less than the duration of the optical excitation. The threshold optical power density does not exceed 3/spl middot/10/sup 3/ W/cm/sup 2/. The proposed device can be used in the fiber input of LTS rapid single flux quantum circuits.
|
|
|
|
Il’in, K. S., Milostnaya, I. I., Verevkin, A. A., Gol’tsman, G. N., Gershenzon, E. M., & Sobolewski, R. (1998). Ultimate quantum efficiency of a superconducting hot-electron photodetector. Appl. Phys. Lett., 73(26), 3938–3940.
Abstract: The quantum efficiency and current and voltage responsivities of fast hot-electron photodetectors, fabricated from superconducting NbN thin films and biased in the resistive state, have been shown to reach values of 340, 220 A/W, and 4×104 V/W,
respectively, for infrared radiation with a wavelength of 0.79 μm. The characteristics of the photodetectors are presented within the general model, based on relaxation processes in the nonequilibrium electron heating of a superconducting thin film. The observed, very high efficiency and sensitivity of the superconductor absorbing the photon are explained by the high multiplication rate of quasiparticles during the avalanche breaking of Cooper pairs.
|
|
|
|
Men’shchikov, E. M., Gogidze, I. G., Sergeev, A. V., Elant’ev, A. I., Kuminov, P. B., Gol’tsman, G. N., et al. (1997). Superconducting fast detector based on the nonequilibrium inductance response of a film of niobium nitride. Tech. Phys. Lett., 23(6), 486–488.
Abstract: A new type of fast detector is proposed, whose operation is based on the variation of the kinetic inductance of a superconducting film caused by nonequilibrium quasiparticles created by the electromagnetic radiation. The speed of the detector is determined by the rate of multiplication of photo-excited quasiparticles, and is nearly independent of the temperature, being less than 1 ps for NbN. Models based on the Owen-Scalapino scheme give a good description of the experimentally determined dependence of the power-voltage sensitivity of the detector on the modulation frequency. The lifetime of the quasiparticles is determined, and it is shown that the reabsorption of nonequilibrium phonons by the condensate has a substantial effect even in ultrathin NbN films 5 nm thick, and results in the maximum possible quantum yield. A low concentration of equilibrium quasiparticles and a high quantum yield result in a detectivity D*=1012 W−1·Hz1/2 at a temperature T=4.2 K and D*=1016 W−1·cm· Hz1/2 at T=1.6 K.
|
|
|
|
Gol’tsman, G. N., & Gershenzon, E. M. (1993). High speed hot-electron superconducting bolometer. In J. R. Birch, & T. J. Parker (Eds.), Proc. SPIE (Vol. 2104, pp. 181–182). SPIE.
Abstract: Physical limitation of response time of a superconducting bolometer as well as the nature of non-equilibrium detection of radiation have been investigated for Al, Nb and NbN thin films in spectral range from submillimeter to near-infraredwavelengths [1,2]. In the case of ideal heat removal from the film with the f_‘. 100A thickness the detection mechanism is an electron heating effect that is not selective to radiation wavelength in a very broad range. The response time ofan electron heating bolometer is determined by an electron-phonon interaction time. This time is of about 10 ns, 0.5 ns and 20 ps for Al, Nb, and NbN correspondingly near the critical temperature of the superconducting film. Thesensitive area of the bolometer consists of a number of narrow strips (with awidth of 1µm) connected in parallel to contact pads; these pads together witha sapphire substrate and a ground plate represent the microstrip transmissionline with an impedance of 50 Q.
|
|
|
|
Yagoubov, P., Kroug, M., Merkel, H., Kollberg, E., Gol'tsman, G., Svechnikov, S., et al. (1998). Noise temperature and local oscillator power requirement of NbN phonon-cooled hot electron bolometric mixers at terahertz frequencies. Appl. Phys. Lett., 73(19), 2814–2816.
Abstract: In this letter, the noise performance of NbN-based phonon-cooled hot electron bolometric quasioptical mixers is investigated in the 0.55–1.1 THz frequency range. The best results of the double-sideband <cd><2018>DSB<cd><2019> noise temperature are: 500 K at 640 GHz, 600 K at 750 GHz, 850 K at 910 GHz, and 1250 K at 1.1 THz. The water vapor in the signal path causes significant contribution to the measured receiver noise temperature around 1.1 THz. The devices are made from 3-nm-thick NbN film on high-resistivity Si and integrated with a planar spiral antenna on the same substrate. The in-plane dimensions of the bolometer strip are typically 0.2Ï«2 um. The amount of local oscillator power absorbed in the bolometer is less than 100 nW.
|
|
